13X分子筛/凹凸棒土颗粒型复合材料吸附Zn2+的研究

Adsorption of Zn2+ by 13X molecular sieve/attapulgite granular composite

以13X分子筛和天然黏土矿物凹凸棒土为原料,制备了13X分子筛/凹凸棒土颗粒型复合材料,并借助扫描电镜、透射电镜、X射线衍射等对复合材料结构与形貌进行表征,考察了不同煅烧温度及不同Zn2+浓度条件下13X分子筛/凹凸棒土颗粒型复合材料对水中Zn2+的吸附行为。结果表明,煅烧温度为550℃时,所制复合材料孔隙结构发达且抗压强度高、吸附性能好;吸附过程符合拟二级动力学,等温吸附实验数据符合Langmuir模型,复合材料对Zn2+的最大吸附量可达99.01mg·g-1;吸附速率的主要控制步骤为颗粒内扩散,此外,吸附过程中同时存在离子交换和化学沉淀。

Based on 13 Xmolecular sieve and natural attapulgite,13 Xmolecular sieve/attapulgite granular composites were prepared,and the morphology and structure of composites were characterized by SEM,TEM,XRD,etc.The adsorption behavior of 13 Xmolecular sieve/attapulgite granular composite for Zn2+in the water was investigated with different calcination temperatures and Zn2+concentrations.The results show that the composite calcined at 550 ℃ has well-developed pore structure,high compressive strength and good absorption property.The adsorption process conforms with the pseudo-secondorder kinetics,isothermal adsorption test data are compliant with the Langmuir model,and the maximum absorption capability of Zn2+by composite reaches 99.01 mg·g-1.The adsorption rate is mainly controlled by intragranular diffusion.In addition,ion exchange and chemical precipitation exist simultaneously in the adsorption process.